Green’s Dictionary of Slang

(US/W.I.) a general term of address, both friendly and otherwise.

1929		C.G. Givens ‘Chatter of Guns’ in Sat. Eve. Post 13 Apr.; list extracted in AS VI:2 (1930) 134: sweets, n. Sweetheart.
1935		R. Chandler ‘Nevada Gas’ in Spanish Blood (1946) 140: The mitts high, sweets!
1953		W. Fisher Waiters 198: Oh yeah, all right, sweets.
1960		C. Cooper Jr Syndicate (1998) 19: This is not for bedtime, sweets — it concerns Chess Horvat.
1969		‘Iceberg Slim’ Mama Black Widow 230: Hello, Baby sweets.
1980		M. Thelwell Harder They Come 144: What you say, sweets?